Julius c



JULIUS o. FUncKE, 0F ELIZABETHTON, rnnnnssnn; nssienon j :ro' AMERroAN GLANZSTOFF coaronnrrornor nnwyonn, n. Y., oo1 ronATIo1\T ;oF DELAWARE DESULPHUBIZATION 7 i No Drawing.

My new invention has to do with a novel and advantageous method for desulphuriz= ing artificial filaments formed by the viscose process.

One object of my invention is to eliminate carbon disulphide.

Another object is to present a process which facilitates the desulphurization of artificial filaments of viscose. 7

Other objects will readily become apparent from a reading of the following specification.

In the manufacture of artificial filaments, films, etc. from viscose, the cellulose is treated with a caustic solution, and then with carbon bisulphide in order to form a Xanthate. This xanthate, in solution, forms viscose. Viscose is extruded, for example, to form filaments, which must be deacidified, bleached, desulphurized, etc. The present invention has to do with a novel method for use in this desulphurization step.

Usually there is a deposit of about 1% of a sulphur on the filaments, giving them a yellowish-gray color. As a desulphurizing means ammonium sulphide may be used. The ammonium sulphide solution acts to dissolve the sulphur, forming ammonium polysulphide.

It has been found that some carbon bisulphide is also retained by the filaments, and I have devised a method whereby this carbon bisulphide may be eliminated. Certain difi'iculties arise through the presence of I a the carbon bisulphide, and it has been found that the desulphurizing agent used is weakened through the formation of trithiocarbonates from the action of the carbon bisulphide therewith.

I have discovered that if an amine is added to the desulphurizing solution the desulphurization is facilitated and the carbon bisulphide removed, because the amine, acting as a catalyzer, combines therewith. Afterwards the compound breaks down to form the original amine plus some sulphides.

I have found that primary amines (such as methylamine CH NH secondary amines (such as dimet-hylamine NH(GH Application filed September 1, 1931." "seiiaijne." 560,667.

or tertiary amines (such as trimethylamine N(CH may be used.

One example of my method follows:

To the desulphurizing solution I add an amine, here aniline, in a proportion of one gram of aniline to one liter of the desulphurizing solution. This solution, here in this example, contains from 10 to 20 grams of ammonium or sodium sulphide per liter. ilhe reactions which take place are as folows:

These equations indicate the manner in which an amine, added as a catalyzer, re-

' step of adding an amine to the desulphurizing medium used..

2. In a process of the class described, the

-moves the carbon bisulphide, Which is detristep of adding to a desulphurizing medium an organic amine that acts as a catalyst.

3. As a desulphurlzlng solution, a solutlon of sodium sulphide, water, and amlne.

4. In a process of the class. described, the

step of desulphurizing a viscose yarn in a solution comprising:

. Percent by weight Ammonium sulphide 10-20 Aniline 1 in water to make up a liter'of solution.

5. In the step of desulphurizing artificial cellulosic products from viscose, the step of adding a catalyst consisting of an amine to the desulphurizin medium used.

6. As a desulp iurizing agent a solution of ammonium sulphide, Water, and an amine.

7. As a desulphurizing medium a solution containing a sulphide of the group consisting of sodium and ammonium, water, and an amine.

8. As a desulphurizing medium a solution 10 comprising a sulphide of the group consist ing of sodium and ammonium Water, and

aniline.

In testimony whereof I afiix my signature.

JULIUS C. FUNCKE. 

